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Welding paste—paste back
 
Abnormal welding—no wetting
IPC-T-50’s definition of no wetting: melted solder cannot form metal combination with base metal (parent metal). Base metal in this standard includes surface coating layer
Defect-class 1,2,3
Solder does not wet onto plate or terminal to be welded.
Solder coverage does not meet requirement of specific solderable terminal.
 
 
Abnormal welding—anti-wetting
IPC-T-50’s definition of anti-wetting: melted solder covers the surface firstly and then shrinks into some solder piles of different shapes. Space among those piles is covered by thin solder film, which protects base metal or surface coating layer.
Defect-class 1,2,3
Anti-wetting makes soldering do not meet solder charging demand of surface mounting or hole plug-in mounting.
 
Abnormal welding—excessive soldering tin—tin ball/tin splash
Defect-class 1,2,3
Tin ball violates minimum electric space.
Tin ball is inside disposable residues, under parylene coating layer or on the surface of metal that is not welded.
 
Abnormal welding—excessive soldering tin—tin bridge
Defect-class 1,2,3
Solder connection beyond conductors that should not be connected.
Solder crosses over adjacent non-access conductors or components
 
 
Abnormal welding—broken solder
Defect-class 1,2,3
Solder is broken or has crack
 
Abnormal welding—broken solder
Defect-class 1,2,3
Solder is broken or has crack
 
Abnormal welding—tin tip
Defect-class 1,2,3
Tin tip violates components’ max height requirement or pin protruding requirement.
Tin tip, as is shown in the graph, violates minimum electric space (1).
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